Blister packages are beneficial to merchandisers in that they provide good product visibility, and therefore attract customer attention to the contained product, in addition to providing bulk to the package, which discourages theft. It is believed that initially all blister packages had complete and uniform adhesion around the flange between the blister and the backing board. When these packages are opened, it is normal for either the board or the blister to be destroyed in the process. In many cases it is desirable that the package be opened with minimal damage to the package. Thus, printed instructions and illustrations are preserved, and the package may continue to serve as a receptacle for the contained product. This is particularly advantageous with multi-use products and products packaged in bulk.
Recloseable blister packages have been developed which, by various means, allow the package to be opened without destruction of either component, and which provide some reclosing feature. A problem with such recloseable blister packages has been that large expanses of the blister flange have intentionally not been affixed to the card when the package is filled and closed. This has been necessitated in packages of the prior art by the need to balance the firm closure of the package with ease and reliability of opening while maintaining the overall integrity of the package.
In particular, the portion of the flange on the opening end of the package has typically been either unaffixed, or adhered with spaced spots of adhesive. Upon opening, spots of adhesive initiate long tears across the face of the board, which damages instructions normally printed on the board, as well as making the product difficult to remove, by leaving strands, or strings, of the front layers of the board attached to the blister flange. In some cases the board is cut scored around the area of the adhesive to provide release of the board spot when the package is opened. In practice, the operation of the cut scored spots has been found to be very sensitive to the depth and uniformity of cut scoring. Cuts made too deep leave insufficient material under the cut to ensure the integrity of the spot with the remainder of the board, and to prevent unintentional release of the blister from the board. Cuts made too shallow, or cuts with slight non-uniformity, can leave a spot which will not separate cleanly from the board and will propagate the tear across the face of the board. Thus frequent adjustments to the cut scoring equipment, and extensive quality testing are necessary in the manufacture of these packages; and the probability of making excessive quantities of unacceptable product is high.
If there are substantial expanses where the blister flange is not affixed to the board, the board and blister flange can be carefully separated a limited distance to create a temporary aperture in the package through which product may be surreptitiously removed, and pilfered. In one development, the portion of the flange on the opening end of the package has been adhered over its entire length, with a cut scored line between the raised product holding portion of the blister and the adhered portion of the flange. As with the cut scoring around spots, mentioned earlier, the operation of the cut scored line has been found to be very sensitive, and to respond similarly, to the depth and uniformity of cut scoring.
Thus recloseable blister packages have heretofore been unable to satisfy the requirement of pilferage resistance in combination with a strong and protective package which can be reliably and easily opened. Those providing adequate pilfer resistance cannot be reliably opened. Those easily opened are subject to unacceptable risk of pilferage. Some are neither adequately pilfer resistant nor reliably opened. Further, the packaging of small items, such as washers or pins, in such recloseable blister packages, has been impossible because of the tendency of the product to fall out of the package through the expanses where the blister flange and the backing board are not affixed. This packaging application would be ideal if the package design defects could be corrected, since such small items are usually sold in quantities greater than what the consumer normally uses at one time.
Illustrative of recloseable blister packages are U. S. Pat. Nos. 3,127,010; 3,174,621; 3,502,486; 3,800,998; 3,942,640; and 4,119,203. While the packages described in those patents may be functional they all suffer from some deficiency either of opening reliability of pilfer resistance. It is desirable that they be recloseable; and it is desirable that the opening and reclosure features be more versatile and adaptable for most efficient use of the packages with a variety of products. It is also desirable that the packages provide improved protection against, and indications of, tampering, that they be made as economically as possible, and that their ease of manufacture be maximized. It is further desirable that the package design be adaptable to protect the product against falling out of the package.
It is therefore an object of this invention to provide a novel, versatile and adaptable, easily opened, blister card package which provides opening without excessive damage to the package, and protection against, and indication of, pilferage or tampering.
It is a further object to provide such a package which is recloseable, and in a form which can be easily manufactured, filled and sealed on existing equipment.
It is yet another object to provide a blister package which is easily opened, easily reclosed, and which readily prevents the product falling out.